Extech PH105 Flat Surface pH Electrode for ExStik PH100/PH110

The Extech PH105 is a flat surface pH electrode designed for direct measurement on surfaces, small volumes, and semi-solid samples. Unlike conventional bulb electrodes, its flat tip allows you to test pH on moist surfaces like paper, agar plates, or skin without a beaker. It plugs directly into Extech PH100 and PH110 ExStik meters, replacing the original electrode module without tools.

Highlights

• Flat surface tip for surface and micro-sample testing
• Compatible with Extech PH100 and PH110 ExStik pH meters
• Gel-filled, single-junction Ag/AgCl reference for low maintenance
• Epoxy body resists breakage in field use
• Measures pH 0 to 14 with meter accuracy support of ±0.01 pH

In daily use

Attach the PH105 to your ExStik meter and calibrate with standard buffers before testing. The flat electrode is ideal for checking pH on surfaces like cheese, meat, or damp soil where immersion is impractical. Rinse with distilled water after each use and store with the protective cap moist to prolong electrode life.

Full specifications

• Electrode type: Flat surface pH electrode
• Measurement range: pH 0 to 14
• Compatibility: Extech PH100 and PH110 ExStik pH meters
• Junction type: Single junction
• Reference type: Ag/AgCl
• Housing material: Epoxy / Plastic
• Electrolyte: Gel
• Temperature compensation: External (via compatible meter)
• Connector type: Direct plug-in (integrated with meter body)
• Response time: <30 seconds
• Operating temperature range: 0 to 60°C (32 to 140°F)
• Storage temperature: 0 to 50°C (32 to 122°F)
• Accuracy support: Supports meter accuracy of ±0.01 pH
• Application: General purpose, surface, small volume, and semi-solid samples
• Calibration: Requires 2 or 3 point calibration with buffer solutions

Final note

The PH105 is a direct replacement electrode for ExStik meters, offering a flat surface design that expands your testing capabilities beyond liquids.